Input device and display device

ABSTRACT

An input device includes a first substrate, a light-emitting element, and a third electrode unit. The first substrate has first and second surfaces. The light-emitting element unit includes: a first conductive electrode unit including first conductive layers; a second conductive electrode unit including second conductive layers each having a size overlapping with the first conductive layer in planar view; and luminescent layers conducted with at least a part of the first electrode unit, each provided between the first and second electrode units and conducted with the first conductive layer and the second conductive layer overlapping with the first conductive layer in planar view. The third electrode unit is insulated from the first conductive layers and detects a change in an electric field between the first conductive layers and the third electrode unit depending on coordinates of a proximity object at a position overlapping with the first surface in planar view.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese Application No.2015-070225, filed on Mar. 30, 2015, the contents of which areincorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present invention relates to an input device and a display devicethat can detect an external proximity object, and in particular to theinput device and the display device that can detect an externalproximity object approaching from the outside based on a change incapacitance.

2. Description of the Related Art

Japanese Patent Application Laid-open Publication No. 2010-198415(JP-A-2010-198415) discloses an input apparatus in which an inputdevice, or so-called a touch panel, and a lighting device, or so-calleda front light, are integrated with each other.

The input apparatus described in JP-A-2010-198415 includes alight-transmissible substrate capable of transmitting light therethroughand arranged at the border between the touch panel and the front lightin a manner shared by them. This configuration reduces the thickness ofthe input apparatus. In recent years, such input apparatuses have beenrequired to have a further reduced thickness.

SUMMARY

According to an aspect, an input device includes a first substrate, alight-emitting element, and a third electrode unit. The first substratehas a first surface and a second surface. The light-emitting elementunit includes: a first conductive electrode unit including firstconductive layers; a second conductive electrode unit including secondconductive layers each having a size overlapping with one of the firstconductive layers in planar view; and luminescent layers electrically incontact with at least a part of the first electrode unit, each of theluminescent layers being provided between the first electrode unit andthe second electrode unit and electrically in contact with one of thefirst conductive layers and one of the second conductive layersoverlapping with the first conductive layer in planar view. The thirdelectrode unit is insulated from the first conductive layers and detectsa change in an electric field between the first conductive layers andthe third electrode unit depending on coordinates of a proximity objectpresent at a position overlapping with the first surface in planar view.

According to another aspect, a display device comprising: an inputdevice including: a first substrate having a first surface and a secondsurface; a light-emitting element unit including a first electrode unitformed on the second surface and including a plurality of firstconductive layers formed in one layer, a second electrode unit formed ina layer different from the layer of the first electrode unit andincluding a plurality of second conductive layers each having a sizeoverlapping with one of the first conductive layers in planar view, anda plurality of luminescent layers electrically in contact with at leasta part of the first electrode unit, each of the luminescent layers beingprovided between the first electrode unit and the second electrode unitand being electrically in contact with one of the first conductivelayers and one of the second conductive layers overlapping with thefirst conductive layer in planar view; and a third electrode unitinsulated from the first conductive layers and that detects a change inan electric field between the first conductive layers and the thirdelectrode unit depending on coordinates of a proximity object present ata position overlapping with the first surface in planar view; and adisplay unit provided on the second surface of the input device andcapable of displaying an image on the first surface thereof.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram for explaining a configuration of a displaydevice according to a first embodiment of the present invention;

FIG. 2 is a diagram for explaining the basic principle of a capacitiveproximity detection technology and illustrates a state where no externalproximity object is in contact with or in proximity to an input device;

FIG. 3 is a diagram for explaining an example of an equivalent circuitin the state where no external proximity object is in contact with or inproximity to the input device illustrated in FIG. 2;

FIG. 4 is a diagram for explaining the basic principle of the capacitiveproximity detection technology and illustrates a state where an externalproximity object is in contact with or in proximity to the input device;

FIG. 5 is a diagram for explaining an example of the equivalent circuitin the state where the external proximity object is in contact with orin proximity to the input device illustrated in FIG. 4;

FIG. 6 is a diagram illustrating an example of waveforms of a drivesignal and a proximity detection signal;

FIG. 7 is a perspective view illustrating an example of drive electrodesand proximity detection electrodes of an input device according to thefirst embodiment;

FIG. 8 is a sectional view schematically illustrating the structure of adisplay device with a proximity detecting function according to thefirst embodiment;

FIG. 9 is a sectional view schematically illustrating the structure ofthe input device according to the first embodiment;

FIG. 10 is another sectional view schematically illustrating thestructure of the input device according to the first embodiment;

FIG. 11 is a diagram for explaining the positional relation in planarview among a first electrode unit, a second electrode unit, and a thirdelectrode unit of the input device according to the first embodiment;

FIG. 12 is a diagram for explaining the positional relation in planarview among the first electrode unit, the second electrode unit, and thethird electrode unit of the input device according to a firstmodification of the first embodiment;

FIG. 13 is a sectional view schematically illustrating the structure ofthe input device according to a second modification of the firstembodiment;

FIG. 14 is a sectional view schematically illustrating the structure ofthe input device according to a third modification of the firstembodiment;

FIG. 15 is a diagram for explaining a first drive electrode driver and asecond drive electrode driver according to the first embodiment;

FIG. 16 is a diagram for explaining voltages of the first electrode unitand the second electrode unit in a drive electrode selection period in astate where a first light-emitting element is turned off;

FIG. 17 is a diagram for explaining voltages of the first electrode unitand the second electrode unit in the drive electrode selection period ina state where the first light-emitting element is turned on;

FIG. 18 is a diagram for explaining voltages of the first electrode unitand the second electrode unit in the drive electrode selection period ina state where the first light-emitting element is turned off;

FIG. 19 is a diagram for explaining voltages of the first electrode unitand the second electrode unit in the drive electrode selection period ina state where the first light-emitting element is turned on;

FIG. 20 is a diagram for explaining the first drive electrode driver andthe second drive electrode driver according to a second embodiment ofthe present invention;

FIG. 21 is a timing chart of drive control according to the secondembodiment; and

FIG. 22 is a timing chart of drive control according to a modificationof the second embodiment.

DETAILED DESCRIPTION

Exemplary aspects (embodiments) according to the present invention aredescribed below in greater detail with reference to the accompanyingdrawings. The contents described in the embodiments are not intended tolimit the present invention. Components described below includecomponents easily conceivable by those skilled in the art and componentssubstantially identical therewith. Furthermore, the components describedbelow can be appropriately combined. The disclosure is given by way ofexample only, and various changes made without departing from the spiritof the invention and easily conceivable by those skilled in the artnaturally fall within the scope of the invention. The drawings maypossibly illustrate the width, the thickness, the shape, and otherelements of each unit more schematically than the actual aspect tosimplify the explanation. These elements, however, are given by way ofexample only and are not intended to limit interpretation of theinvention. In the specification and the figures, components similar tothose previously described with reference to a preceding figure aredenoted by like reference numerals, and overlapping explanation thereofwill be appropriately omitted.

First Embodiment

FIG. 1 is a block diagram for explaining a configuration of a displaydevice according to a first embodiment of the present invention. Adisplay system 100 includes a display device 1 with a proximitydetecting function, a control unit 11, a gate driver 12, a source driver13, a source selector 13S, a first electrode driver 14, a secondelectrode driver 15, and a proximity detecting unit 40. In the displaydevice 1 with a proximity detecting function, a reflective display unit9 and an input device 2 are stacked in a manner overlapping with eachother in planar view, which will be described below. The display unit 9serves as a reflective liquid-crystal display unit, and the input device2 serves as a capacitive touch panel.

The display unit 9 sequentially scans each horizontal line based on ascanning signal Vscan supplied from the gate driver 12, therebyperforming display, which will be described below. The control unit 11is a circuit that supplies control signals to the gate driver 12, thesource driver 13, the first electrode driver 14, the second electrodedriver 15, and the proximity detecting unit 40 based on video signalsVdisp supplied from the outside, thereby performing control such thatthese components operate in synchronization with one another. A controldevice according to the present invention includes the control unit 11,the gate driver 12, the source driver 13, the first electrode driver 14,the second electrode driver 15, and the proximity detecting unit 40.

The gate driver 12 has a function to sequentially select one horizontalline to be a target of display drive in the display unit 9 based on thecontrol signal supplied from the control unit 11.

The source driver 13 is a circuit that supplies pixel signals Vpix topixels (sub-pixels) arranged in a matrix on the display surface of thedisplay unit 9 based on the control signal supplied from the controlunit 11. The source driver 13 generates an image signal Vsig bytime-division multiplexing the pixel signals Vpix for a plurality ofsub-pixels in the display unit 9 from the control signal of onehorizontal line. The source driver 13 then supplies the image signalVsig to the source selector 13S. The source driver 13 generates a switchcontrol signal Vsel required to separate the pixel signals Vpixmultiplied into the image signal Vsig. The source driver 13 thensupplies the switch control signal Vsel to the source selector 13Stogether with the image signal Vsig. With this configuration, the sourceselector 13S requires a smaller number of wiring between the sourcedriver 13 and the source selector 13S.

The first electrode driver 14 is a circuit that supplies a drive signalpulse based on a drive signal to a first electrode unit, which will bedescribed below, of the input device 2 based on the control signalsupplied from the control unit 11.

The second electrode driver 15 is a circuit that supplies a drive signalVel to a second electrode unit, which will be described below, of theinput device 2 based on the control signal supplied from the controlunit 11.

The proximity detecting unit 40 is a circuit that detects whether aproximity state is created on the input device 2 based on the controlsignal supplied from the control unit 11 and a proximity detectionsignal Vdet supplied from the input device 2. If detecting the proximitystate, the proximity detecting unit 40 derives the coordinates and thelike of the proximity detection area. The proximity detecting unit 40includes a proximity detection signal amplifying unit 42, ananalog/digital (A/D) converting unit 43, a signal processing unit 44, acoordinate extracting unit 45, and a detection timing control unit 46.

The proximity detection signal amplifying unit 42 amplifies theproximity detection signal Vdet supplied from the input device 2. Theproximity detection signal amplifying unit 42 may include an analoglow-pass filter that removes high-frequency components (noisecomponents) included in the proximity detection signal Vdet and extractsand outputs the component of the proximity detection signal Vdet.

Basic Principle of Capacitive Proximity Detection

The input device 2 operates based on the basic principle of capacitiveproximity detection and outputs the proximity detection signal Vdet. Thefollowing describes the basic principle of proximity detection in theinput device 2 with reference to FIGS. 1 to 6. FIG. 2 is a diagram forexplaining the basic principle of a capacitive proximity detectiontechnology and illustrates a state where no external proximity object isin contact with or in proximity to the input device 2. FIG. 3 is adiagram for explaining an example of an equivalent circuit in the statewhere no external proximity object is in contact with or in proximity tothe input device 2 illustrated in FIG. 2. FIG. 4 is a diagram forexplaining the basic principle of the capacitive proximity detectiontechnology and illustrates a state where an external proximity object isin contact with or in proximity to the input device 2. FIG. 5 is adiagram for explaining an example of the equivalent circuit in the statewhere the external proximity object is in contact with or in proximityto the input device 2 illustrated in FIG. 4. FIG. 6 is a diagramillustrating an example of waveforms of a drive signal and a proximitydetection signal.

As illustrated in FIG. 2, for example, a capacitive element C1 includesa pair of electrodes, i.e., a drive electrode E1 and a proximitydetection electrode E2, arranged facing each other with a dielectric Dinterposed therebetween. As illustrated in FIG. 3, one end of thecapacitive element C1 is coupled to an alternating-current (AC) signalsource (drive signal source) S, whereas the other end thereof is coupledto a voltage detector (proximity detecting unit) DET. The voltagedetector DET is an integration circuit included in the proximitydetection signal amplifying unit 42 illustrated in FIG. 1, for example.

When the AC signal source S applies a drive signal pulse Sg, which is anAC rectangular wave, at a predetermined frequency (e.g., severalkilohertz to several hundred kilohertz) to the drive electrode E1 (oneend of the capacitive element C1), an output waveform (proximitydetection signal Vdet) is generated via the voltage detector DET coupledto the proximity detection electrode E2 (the other end of the capacitiveelement C1).

In a non-proximity state (including a non-contact state) where noexternal proximity object (e.g., a finger or a stylus pen) is inproximity to (or in contact with) the input device 2, an electriccurrent I₀ depending on the capacitance value of the capacitive elementC1 flows in association with charge and discharge of the capacitiveelement C1 as illustrated in FIGS. 2 and 3. As illustrated in FIG. 6,the voltage detector DET converts fluctuations in the electric currentI₀ depending on the drive signal pulse Sg into fluctuations in thevoltage (waveform V₀ indicated by the solid line).

On the other hand, in a proximity state (including a contact state)where an external proximity object is in proximity to (or in contactwith) the input device 2, capacitance C2 generated by the externalproximity object is in contact with or in proximity to the proximitydetection electrode E2 as illustrated in FIG. 4. The presence of thecapacitance C2 blocks capacitance of a fringe between the driveelectrode E1 and the proximity detection electrode E2, thereby providinga capacitive element C1′ having a capacitance value smaller than that ofthe capacitive element C1. In the equivalent circuit illustrated in FIG.5, an electric current I₁ flows through the capacitive element C1′. Asillustrated in FIG. 6, the voltage detector DET converts fluctuations inthe electric current depending on the drive signal pulse Sg intofluctuations in the voltage (waveform V₁ indicated by the dotted line).In this case, the waveform V₁ has amplitude smaller than that of thewaveform V₀. As a result, an absolute value |ΔV| of the voltagedifference between the waveform V₀ and the waveform V₁ varies dependingon the influence of an object, such as the external proximity object,approaching the input device 2 from the outside. To accurately detectthe absolute value |ΔV| of the voltage difference between the waveformV₀ and the waveform V₁, the voltage detector DET preferably performs theoperation with a period Reset to reset charge and discharge of acapacitor based on the frequency of the drive signal pulse Sg byswitching in the circuit.

The input device 2 illustrated in FIG. 1 sequentially scans eachdetection block in response to the drive signal supplied from the firstelectrode driver 14, thereby performing proximity detection.

The input device 2 outputs the proximity detection signal Vdet for eachdetection block from a plurality of proximity detection electrodes,which will be described below, via the voltage detector DET illustratedin FIG. 3 or FIG. 5. The input device 2 thus supplies the proximitydetection signal Vdet to the proximity detection signal amplifying unit42 of the proximity detecting unit 40. The proximity detection signalamplifying unit 42 amplifies the proximity detection signal Vdet andsupplies it to the A/D converting unit 43.

The A/D converting unit 43 is a circuit that samples an analog signaloutput from the proximity detection signal amplifying unit 42 at timingsynchronized with the drive signal, thereby converting the analog signalinto a digital signal.

The signal processing unit 44 includes a digital filter that reducesfrequency components (noise components) other than the frequency atwhich the drive signal is sampled in the output signal from the A/Dconverting unit 43. The signal processing unit 44 is a logic circuitthat detects whether a touch is made on the input device 2 based on theoutput signal from the A/D converting unit 43. The signal processingunit 44 performs processing for extracting only the voltage differencecaused by the external proximity object. The signal of the voltagedifference caused by the external proximity object corresponds to theabsolute value |ΔV| of the difference between the waveform V₀ and thewaveform V₁. The signal processing unit 44 may perform an arithmeticoperation for averaging the absolute values |ΔV| per detection block,thereby calculating the average value of the absolute values |ΔV|. Thesignal processing unit 44 thus can reduce the influence of noise. Thesignal processing unit 44 compares the signal of the detected voltagedifference caused by the external proximity object with a predeterminedthreshold voltage. If the voltage difference is equal to or larger thanthe threshold voltage, the signal processing unit 44 determines that theexternal proximity object is in the proximity state. On the other hand,if the voltage difference is determined to be smaller than the thresholdvoltage as a result of comparison between the detected digital voltageand the predetermined threshold voltage, the signal processing unit 44determines that the external proximity object is in the non-proximitystate. The proximity detecting unit 40 thus performs proximitydetection.

The coordinate extracting unit 45 is a logic circuit that derives, whena proximity state is detected by the signal processing unit 44, thecoordinate position at which the proximity state is created in the planeof the detection area. The detection timing control unit 46 performscontrol such that the A/D converting unit 43, the signal processing unit44, and the coordinate extracting unit 45 operate in synchronizationwith one another. The coordinate extracting unit 45 outputs thecoordinates of the proximity object as an output signal Vout.

FIG. 7 is a perspective view illustrating an example of the driveelectrodes and the proximity detection electrodes of the input deviceaccording to the first embodiment. The input device 2 includes a firstelectrode unit 31, a second electrode unit 32, and a third electrodeunit 33 insulated from the first electrode unit 31 and the secondelectrode unit 32. The first electrode unit 31 has a plurality of stripeelectrode patterns extending in a predetermined extending direction of aconductor pattern. The electrode patterns serve as drive electrodes Tx1,Tx2, Tx3, . . . , Txn (hereinafter, which may be referred to as driveelectrodes Tx) from which the drive signal pulse Sg is applied.

The second electrode unit 32 has a plurality of stripe electrodepatterns extending in a predetermined extending direction of a conductorpattern. The electrode patterns serve as drive electrodes Tz1, Tz2, Tz3,. . . , Tzn (hereinafter, which may be referred to as drive electrodesTz) from which the drive signal pulse Sg is applied. The driveelectrodes Tz correspond one-to-one to the drive electrodes Tx facingthem. A drive electrode Tz facing a drive electrode Tx to which thedrive signal pulse Sg is applied is synchronously supplied with the samedrive signal pulse Sg.

The third electrode unit 33 has a plurality of stripe electrode patternsextending in a direction intersecting with the extending direction ofthe first electrode unit 31. The electrode patterns serve as proximitydetection electrodes Rx1, Rx2, Rx3, . . . , Rxm (hereinafter, which maybe referred to as proximity detection electrodes Rx) that output theproximity detection signal Vdet. The electrode patterns of the proximitydetection electrodes Rx are coupled to respective input terminals of theproximity detection signal amplifying unit 42 of the proximity detectingunit 40.

In the input device 2 according to the first embodiment illustrated inFIG. 7, the proximity detection electrodes Rx face the drive electrodesTx. The proximity detection electrodes Rx do not necessarily face thedrive electrodes Tx and may be provided in the same layer as that of thedrive electrodes Tx. The proximity detection electrodes Rx or the driveelectrodes Tx do not necessarily have a stripe shape, i.e., a shapedivided into a plurality of portions and may have a comb shape, forexample. Alternatively, any shape can be employed for the proximitydetection electrodes Rx or the first electrode unit 31 (drive electrodeblock), as long as being divided into a plurality of portions. In thiscase, the shape of the slits dividing the first electrode unit 31 may bea straight line or a curve.

The drive electrode E1 illustrated in FIG. 2 corresponds to each of thedrive electrodes Tx illustrated in FIG. 7. The proximity detectionelectrode E2 illustrated in FIG. 2 corresponds to each of the proximitydetection electrodes Rx illustrated in FIG. 7. With this configuration,capacitance corresponding to the capacitance value of the capacitiveelement C1 illustrated in FIG. 2 is generated at the intersections atwhich the drive electrodes Tx intersect with the proximity detectionelectrodes Rx in planar view illustrated in FIG. 7.

The following describes the structure of the display device 1 with aproximity detecting function. FIG. 8 is a sectional view schematicallyillustrating the structure of the display device with a proximitydetecting function according to the first embodiment. The display unit 9according to the first embodiment is a reflective image display panel.The display unit 9 may be a transflective image display panel and simplyneeds to be a display device that displays an image by reflectingincident light entering from the observer 200 side. As illustrated inFIG. 8, the display unit 9 includes an array substrate 91 and a countersubstrate 92 facing each other. A liquid-crystal layer 93 in whichliquid-crystal elements are sealed is provided between the arraysubstrate 91 and the counter substrate 92.

The array substrate 91 is a transparent light-transmissive substrate,such as a glass substrate. The array substrate 91 includes a pluralityof pixel electrodes 94 on the surface of an insulation layer 98 on theliquid-crystal layer 93 side. The pixel electrodes 94 are coupled tosignal lines via respective switching elements 99. The pixel signalsVpix described above are applied to the pixel electrodes 94. The pixelelectrodes 94 are made of a material having metallic luster, such asaluminum and silver, and have light reflectivity. With this structure,the pixel electrodes 94 reflect external light or light from the inputdevice 2.

The counter substrate 92 is a transparent light-transmissive substrate,such as a glass substrate. The counter substrate 92 includes a counterelectrode 95 and color filters 96 on the surface on the liquid-crystallayer 93 side. More specifically, the counter electrode 95 is providedon the surface of the color filters 96 on the liquid-crystal layer 93side.

The counter electrode 95 is made of a transparent light-transmissiveconductive material, such as indium tin oxide (ITO) and indium zincoxide (IZO). The counter electrode 95 is supplied with a commonpotential common to the pixels. When a voltage generated by an imageoutput signal is applied between the pixel electrodes 94 and the counterelectrode 95 facing each other, the pixel electrodes 94 and the counterelectrode 95 generate an electric field in the liquid-crystal layer 93.The electric filed generated in the liquid-crystal layer 93 causes theliquid-crystal elements to twist and changes the birefringence, therebyadjusting the amount of light from the display unit 9 in each sub-pixel97. While the display unit 9 is what is called a vertical-electric-fielddisplay unit, it may be a lateral-electric-field display unit thatgenerates an electric field in a direction parallel to the displaysurface.

The color filter 96 of any one of a first color (e.g., red R), a secondcolor (e.g., green G), and a third color (e.g., blue B) is provided toeach sub-pixel 97 in a manner correspondingly to the pixel electrode 94.The pixel electrode 94, the counter electrode 95, and the color filter96 of each color constitute the sub-pixel 97.

The input device 2 can output light toward the display unit 9 in an LF1direction. The input device 2 is provided above the surface of thecounter substrate 92 on the side opposite to the liquid-crystal layer93. The display unit 9 uses the input device 2 as a front light, whichwill be described below, and reflects, in an LF2 direction, the lightthat has entered in the LF1 direction, thereby displaying an image. Thepixel electrode 94 reflects, in the LF2 direction, the light that hasentered in the LF1 direction from the surface on the observer 200 side(surface on which an image is displayed), for example. The input device2 is bonded to the counter substrate 92 with an optical adhesive layer8. The optical adhesive layer 8 is preferably made of a material havinga light-scattering function. The light output from the input device 2 inthe LF1 direction is scattered by the optical adhesive layer 8. Withthis configuration, the pixel electrode 94 is likely to be uniformlyirradiated with the light from the input device 2. A polarizing platemay be further provided at the position of the optical adhesive layer 8.

FIG. 9 is a sectional view schematically illustrating the structure ofthe input device according to the first embodiment. FIG. 10 is anothersectional view schematically illustrating the structure of the inputdevice according to the first embodiment. FIG. 11 is a view forexplaining the positional relation in planar view among the firstelectrode unit, the second electrode unit, and the third electrode unitof the input device according to the first embodiment. The sectionillustrated in FIG. 9 is a section along line X-X in FIG. 11, whereasthe section illustrated in FIG. 10 is a section along line IX-IX in FIG.11. As illustrated in FIGS. 9 and 10, the input device 2 includes afirst substrate 21, the first electrode unit 31, the second electrodeunit 32, a luminescent layer 22, the third electrode unit 33, and afirst light-blocking unit 24. The second electrode unit 32 is coveredwith an insulating protective layer 23. The insulating protective layer23 is not necessarily provided. The first substrate 21 is alight-transmissive substrate, such as a glass substrate, having a firstsurface 201 and a second surface 202. In the input device 2, the firstsurface 201 in FIGS. 9 and 10 is provided on the observer 200 sideillustrated in FIG. 8, and the second surface 202 is provided on thedisplay unit 9 side.

The first electrode unit 31 includes a plurality of first conductivelayers formed in one layer on the second surface 202 side of the firstsubstrate 21. The first conductive layers have a shape continuouslyextending in one direction in planar view and are in contact with theluminescent layer 22 along the shape of the first conductive layers. Thefirst conductive layers of the first electrode unit 31 are made of atransparent light-transmissive conductive material or a conductive metalmaterial, such as ITO and IZO. The first conductive layers of the firstelectrode unit 31 can reflect light emitted from the luminescent layer22 when they are made of a metal material having metallic luster, suchas aluminum (Al), silver (Ag), and chromium (Cr), and an alloycontaining these metals.

The first light-blocking unit 24 is arranged between the first substrate21 and the first electrode unit 31. The first light-blocking unit 24 isprovided along the shape of the first conductive layer of the firstelectrode unit 31. The first light-blocking unit 24 has an area largerthan that of the first conductive layer of the first electrode unit 31.The first light-blocking unit 24 can cover the whole area of the firstconductive layer of the first electrode unit 31 viewed in a directionperpendicular to the first surface 201 of the first substrate 21.

The first light-blocking unit 24 may be made of any desired material aslong as it has a light-blocking property. The first light-blocking unit24 is preferably made of a metal material having metallic luster, suchas Al, Ag, and Cr, and an alloy containing these metals to reflect lightemitted from the luminescent layer 22. A first light-emitting elementunit DEL thus includes the first light-blocking unit 24 provided closerto the first surface 201 of the first substrate 21 than the luminescentlayer 22, thereby preventing light from leaking toward the first surface201 of the first substrate 21.

The luminescent layer 22 has a size overlapping with one of the firstconductive layers in planar view. As illustrated in FIGS. 9 and 10, theluminescent layer 22 is provided between the first electrode unit 31 andthe second electrode unit 32. The luminescent layer 22 is electricallyin contact with the first conductive layer of the first electrode unit31. The luminescent layer 22 is an organic luminescent layer andcontains an organic material. The luminescent layer 22 includes a holeinjection layer, a hole transport layer, an organic layer, an electrontransport layer, and an electron injection layer, which are notillustrated.

The second electrode unit 32 is second conductive layers formed in alayer different from that of the first electrode unit 31. Each secondconductive layer has a size overlapping with one of the first conductivelayers in planar view. The second conductive layer of the secondelectrode unit 32 is electrically in contact with the entire surface ofthe luminescent layer 22. The second conductive layers of the secondelectrode unit 32 are made of a transparent light-transmissiveconductive material, such as ITO and IZO.

The first light-emitting element unit DEL includes the first electrodeunit 31, the luminescent layer 22, and the second electrode unit 32. Theluminescent layer 22 emits light by a forward-bias voltage being appliedto the first electrode unit 31 and the second electrode unit 32. Whenthe voltage is applied, the luminescent layer 22 in the firstlight-emitting element unit DEL can emit light along the shape of thefirst conductive layers of the first electrode unit 31. As a result,light-emitting bands are generated in a manner continuously extending inone direction in planar view. The input device 2 thus functions as afront light that can output light to the display unit 9 illustrated inFIG. 8.

Assuming that the first electrode unit 31 serves as a cathode, and thesecond electrode unit 32 serves as an anode, the first conductive layersof the first electrode unit 31 may be made only of a metal, such as Aland Ag, and the second conductive layers of the second electrode unit 32may be made of ITO. When the first electrode unit 31 serves as an anode,the first conductive layers of the first electrode unit 31 may be madeof Al with ITO sputtered thereon. In a case where the second electrodeunit 32 serves as a cathode, the second conductive layers of the secondelectrode unit 32 may be made of IZO.

The third electrode unit 33 is provided on the first surface 201 of thefirst substrate 21 and is insulated from the first conductive layers ofthe first electrode unit 31. The third electrode unit 33 includes aplurality of third conductive layers formed in one layer different fromthat of the first conductive layers of the first electrode unit 31. Thefirst surface 201 on which the third electrode unit 33 is formed is areference plane (coordinate input reference plane) serving as areference for input coordinates of the proximity object.

As described above, the first electrode unit 31 and the second electrodeunit 32 respectively correspond to the drive electrodes Tx and the driveelectrodes Tz from which the drive signal pulse Sg is applied, whereasthe third electrode unit 33 corresponds to the proximity detectionelectrodes Rx (refer to FIG. 7). When the input device 2 performs aproximity detection operation, the third electrode unit 33 can output,to the proximity detecting unit 40 (refer to FIG. 1), a change in theelectric field between the first electrode unit 31 and the thirdelectrode unit 33 depending on the coordinates of the proximity objectpresent at a position overlapping with the first surface 201 of thefirst substrate 21 in planar view.

To manufacture the input device 2, the first substrate 21 is prepared,and the first light-blocking unit 24 is patterned on the second surface202 of the first substrate 21. Gaps between adjacent firstlight-blocking units 24 are planarized by an insulation layer 23 a.Subsequently, the first conductive layer of the first electrode unit 31is patterned on the first light-blocking unit 24. Gaps between adjacentfirst conductive layers of the first electrode unit 31 are planarized byan insulation layer 23 b. Subsequently, the luminescent layer 22 and theadjacent second conductive layers of the second electrode unit 32 areformed on the first conductive layers of the first electrode unit 31 andthe insulation layer 23 b. Gaps between adjacent luminescent layers 22and adjacent second conductive layers of the second electrode unit 32are planarized by an insulation layer 23 c. Subsequently, an insulationlayer 23 d made of an insulator is formed in the input device 2. Asdescribed above, the protective layer 23 includes the insulation layer23 a, the insulation layer 23 b, the insulation layer 23 c, and theinsulation layer 23 d. The insulation layers 23 a, 23 b, 23 c, and 23 dare light-transmissive insulators, such as alumina (Al₂O₃). Theinsulation layers 23 a, 23 b, 23 c, and 23 d may be made of differentmaterials as long as they are insulators. Subsequently, the thirdelectrode unit 33 is formed on the first surface 201 of the firstsubstrate 21 in the input device 2. As described above, the input device2 according to the first embodiment can be manufactured with a smallernumber of etching processes, thereby reducing manufacturing cost.

First Modification of the First Embodiment

The following describes the input device 2 according to a firstmodification of the first embodiment. FIG. 12 is a diagram forexplaining the positional relation in planar view among the firstelectrode unit, the second electrode unit, and the third electrode unitof the input device according to the first modification of the firstembodiment. Components identical with those described in the firstembodiment are denoted by like reference numerals, and overlappingexplanation thereof will be omitted.

As illustrated in FIG. 12, the input device 2 according to the firstmodification of the first embodiment is different from the input device2 according to the first embodiment in that it does not include thefirst light-blocking unit 24.

Second Modification of the First Embodiment

The following describes the input device 2 according to a secondmodification of the first embodiment. FIG. 13 is a sectional viewschematically illustrating the structure of the input device accordingto the second modification of the first embodiment. The sectionillustrated in FIG. 13 is a section of the modification along line X-Xin FIG. 11. In the input device according to the second modification ofthe first embodiment illustrated in FIG. 13, the positional relation inplanar view among the first electrode unit, the second electrode unit,and the third electrode unit is the same as that illustrated in FIG. 11.Components identical with those described in the first embodiment aredenoted by like reference numerals, and overlapping explanation thereofwill be omitted.

The input device 2 according to the second modification of the firstembodiment includes the first substrate 21, an insulation layer 25, thefirst electrode unit 31, the second electrode unit 32, the luminescentlayer 22, the third electrode unit 33, and the first light-blocking unit24. The third electrode unit 33 according to the second modification ofthe first embodiment is provided on the second surface 202 of the firstsubstrate 21 and is insulated from the first conductive layers of thefirst electrode unit 31 by the insulation layer 25. The first surface201 of the first substrate 21 on the side opposite to the second surface202 on which the third electrode unit 33 is formed is a reference plane(coordinate input reference plane) serving as a reference for inputcoordinates of the proximity object. As illustrated in FIG. 13, thefirst electrode unit 31, the second electrode unit 32, and the thirdelectrode unit 33 are provided on the second surface 202 side of thefirst substrate 21.

As described above, the first electrode unit 31 and the second electrodeunit 32 respectively correspond to the drive electrodes Tx and the driveelectrodes Tz from which the drive signal pulse Sg is applied, whereasthe third electrode unit 33 corresponds to the proximity detectionelectrodes Rx (refer to FIG. 7). When the input device 2 performs aproximity detection operation, the third electrode unit 33 can output,to the proximity detecting unit 40 (refer to FIG. 1), a change in theelectric field between the first electrode unit 31 and the thirdelectrode unit 33 depending on the coordinates of the proximity objectpresent at a position overlapping with the first surface 201 of thefirst substrate 21 in planar view.

Third Modification of the First Embodiment

The following describes the input device 2 according to a thirdmodification of the first embodiment. FIG. 14 is a sectional viewschematically illustrating the structure of the input device accordingto the third modification of the first embodiment.

In the input device according to the third modification of the firstembodiment illustrated in FIG. 14, the positional relation in planarview among the first electrode unit, the second electrode unit, and thethird electrode unit is the same as that illustrated in FIG. 11.Components identical with those described in the first embodiment andthe modifications thereof are denoted by like reference numerals, andoverlapping explanation thereof will be omitted.

The input device 2 includes a cover substrate 26, the insulation layer25, the first substrate 21, the first electrode unit 31, the secondelectrode unit 32, the luminescent layer 22, the third electrode unit33, and the first light-blocking unit 24. The cover substrate 26 is alight-transmissive substrate, such as a glass substrate. The thirdelectrode unit 33 according to the third modification of the firstembodiment is provided on the surface of the cover substrate 26 facingthe first substrate 21 and on the second surface 201 side of the firstsubstrate 21. The cover substrate 26 and the first substrate 21 arelaminated with the insulation layer 25 interposed therebetween and areinsulated from each other. The first surface 201 of the first substrate21 according to the third modification of the first embodiment is areference plane (coordinate input reference plane) serving as areference for input coordinates of the proximity object. The surface ofthe cover substrate 26 on the side opposite to the side provided withthe third electrode unit 33 is substantially parallel to the firstsurface 201 of the first substrate 21.

As described above, the first electrode unit 31 corresponds to the driveelectrodes Tx from which the drive signal pulse Sg is applied, whereasthe third electrode unit 33 corresponds to the proximity detectionelectrodes Rx (refer to FIG. 7). When the input device 2 performs aproximity detection operation, the third electrode unit 33 can output,to the proximity detecting unit 40 (refer to FIG. 1), a change in theelectric field between the first electrode unit 31 and the thirdelectrode unit 33 depending on the coordinates of the proximity objectpresent at a position overlapping with the first surface 201 of thefirst substrate 21 in planar view.

As described above, the first electrode unit 31 and the second electrodeunit 32 according to the first embodiment and the modifications thereoffunction as electrodes of the first light-emitting element unit DEL andalso respectively function as the drive electrodes Tx and the driveelectrodes Tz of the input device 2. This configuration can reduce thethickness of the input device 2.

Drive Control

The following describes drive control of the input device 2 according tothe first embodiment and the modifications thereof with reference toFIGS. 1, 7, and 15 to 19. When the input device 2 performs a proximitydetection operation, the first electrode driver 14 illustrated in FIG. 1performs driving to sequentially scan the drive electrodes Txillustrated in FIG. 7 in a time-division manner. As a result, the driveelectrodes Tx of the first electrode unit 31 are sequentially selectedin a scanning direction Scan. The input device 2 then outputs theproximity detection signal Vdet from the proximity detection electrodesRx. The first electrode driver 14 of the input device 2 may performdriving to sequentially scan each detection block including a pluralityof drive electrodes Tx illustrated in FIG. 7 in a time-division manner.

The first electrode unit 31 functions as electrodes of the firstlight-emitting element unit DEL and also functions as the driveelectrodes Tx of the input device 2. Therefore, the first light-emittingelement unit DEL may emit light even if not necessary, by the drivesignal pulse Sg being applied to the drive electrodes Tx of the firstelectrode unit 31. To address this, the input device 2 according to thefirst embodiment and the modifications thereof employs a driving methodfor suppressing unintended emission of light from the firstlight-emitting element unit DEL even when the drive signal pulse Sg isapplied to the drive electrodes Tx of the first electrode unit 31.

FIG. 15 is a diagram for explaining a first drive electrode driver and asecond drive electrode driver according to the first embodiment. Thefirst electrode driver 14 includes a first electrode control unit 141and a Tx buffer 16. The first electrode control unit 141 generates adrive signal Vtx based on the control signal supplied from the controlunit 11 and supplies it to the Tx buffer 16. Based on the drive signalVtx, the Tx buffer 16 supplies the amplified drive signal pulse Sg tothe drive electrode Txn (a part of the first electrode unit 31)sequentially selected in the scanning direction Scan.

The second electrode driver 15 includes a second electrode control unit151 and a voltage control circuit 17. The second electrode control unit151 transmits a control signal ELbev for supplying electric power at acertain voltage to the voltage control circuit 17. The voltage controlcircuit 17 controls the voltage supplied to the second electrode unit 32of the input device 2 based on the control signal supplied from thecontrol unit 11. Similarly to the Tx buffer 16, the voltage controlcircuit 17 supplies the amplified drive signal pulse Sg to the driveelectrode Tzn (a part of the second electrode unit 32) sequentiallyselected in the scanning direction Scan based on the drive signal Vtx.

FIG. 16 is a diagram for explaining voltages of the first electrode unitand the second electrode unit in a drive electrode selection period in astate where a first light-emitting element is turned off. FIG. 17 is adiagram for explaining voltages of the first electrode unit and thesecond electrode unit in the drive electrode selection period in a statewhere the first light-emitting element is turned on. In FIGS. 16 and 17,the first electrode unit 31 serves as a cathode of the firstlight-emitting element unit DEL, whereas the second electrode unit 32serves as an anode of the first light-emitting element unit DEL.

To turn off the first light-emitting element unit DEL, the voltagecontrol circuit 17 makes a voltage Va of the second electrode unit 32closer to a voltage Vk of the first electrode unit 31, therebypreventing the voltage difference between the voltage Vk of the firstelectrode unit 31 and the voltage Va of the second electrode unit 32from reaching a forward light-emitting drive voltage ΔVFL. In thisstate, the first electrode driver 14 applies the drive signal pulse Sgto the first electrode unit 31 as illustrated in FIG. 16. The secondelectrode driver 15 applies the drive signal pulse Sg to a part of thesecond electrode unit 32 overlapping in planar view with a part of thefirst electrode unit 31 to which the first electrode driver 14 hasapplied the drive signal pulse Sg. The rising direction of the drivesignal pulse Sg applied by the first electrode driver 14 is the same asthat applied by the second electrode driver 15. Even when the drivesignal pulse Sg is applied in a drive selection period Htx, thisconfiguration prevents the potential difference between the firstelectrode unit 31 and the second electrode unit 32 from exceeding thelight-emitting drive voltage ΔVFL at which the first light-emittingelement unit DEL is turned on, thereby suppressing emission of lightfrom the first light-emitting element unit DEL. As a result, when thefirst electrode driver 14 and the second electrode driver 15 performdriving to sequentially scan the drive electrodes Tx and the driveelectrodes Tz, respectively, in a time-division manner, it is possibleto suppress emission of light from the first light-emitting element unitDEL caused by either of the drive signal pulses Sg.

To turn on the first light-emitting element unit DEL, the voltagecontrol circuit 17 performs control to make the difference between thevoltage Vk of the first electrode unit 31 and the voltage Va of thesecond electrode unit 32 closer to the forward-bias light-emitting drivevoltage ΔVFL. As illustrated in FIG. 17, the voltage control circuit 17applies a forward-bias voltage of equal to or larger than thelight-emitting drive voltage ΔVFL between the first electrode unit 31and the second electrode unit 32.

As illustrated in FIG. 17, the first electrode driver 14 applies thedrive signal pulse Sg to the first electrode unit 31. The secondelectrode driver 15 applies the drive signal pulse Sg to a part of thesecond electrode unit 32 overlapping in planar view with a part of thefirst electrode unit 31 to which the first electrode driver 14 hasapplied the drive signal pulse Sg. Even when the drive signal pulse Sgis applied in the drive selection period Htx, this configuration makesthe potential difference between the first electrode unit 31 and thesecond electrode unit 32 equal to or larger than the light-emittingdrive voltage ΔVFL. Even when the drive signal pulse Sg is applied, thefirst light-emitting element unit DEL continues to emit light. Thelighting amount of the first light-emitting element unit DEL variesdepending on the voltage Va of the second electrode unit 32 controlledby the voltage control circuit 17 based on an instruction from thecontrol unit 11.

The first electrode unit 31 may serve as an anode of the firstlight-emitting element unit DEL, and the second electrode unit 32 mayserve as a cathode of the first light-emitting element unit DEL. FIG. 18is a diagram for explaining voltages of the first electrode unit and thesecond electrode unit in the drive electrode selection period in a statewhere the first light-emitting element is turned off. FIG. 19 is adiagram for explaining voltages of the first electrode unit and thesecond electrode unit in the drive electrode selection period in a statewhere the first light-emitting element is turned on. In FIGS. 18 and 19,the first electrode unit 31 serves as an anode of the firstlight-emitting element unit DEL, whereas the second electrode unit 32serves as a cathode of the first light-emitting element unit DEL.

To turn off the first light-emitting element unit DEL, the voltagecontrol circuit 17 makes the voltage Vk of the second electrode unit 32closer to the voltage Va of the first electrode unit 31, therebypreventing the voltage difference between the voltage Va of the firstelectrode unit 31 and the voltage Vk of the second electrode unit 32from reaching the forward light-emitting drive voltage ΔVFL. In thisstate, the first electrode driver 14 applies the drive signal pulse Sgbetween the first electrode unit 31 and the second electrode unit 32 asillustrated in FIG. 18. The second electrode driver 15 applies the drivesignal pulse Sg to a part of the second electrode unit 32 overlapping inplanar view with a part of the first electrode unit 31 to which thefirst electrode driver 14 has applied the drive signal pulse Sg. Evenwhen the drive signal pulse Sg is applied in the drive selection periodHtx, this configuration prevents the potential difference between thefirst electrode unit 31 and the second electrode unit 32 from exceedingthe light-emitting drive voltage ΔVFL at which the first light-emittingelement unit DEL is turned on, thereby suppressing emission of lightfrom the first light-emitting element unit DEL. As a result, the firstelectrode driver 14 and the second electrode driver 15 perform drivingto sequentially scan the drive electrodes Tx and the drive electrodesTz, respectively, in a time-division manner, thereby suppressingemission of light from the first light-emitting element unit DEL causedby either of the drive signal pulses Sg.

To turn on the first light-emitting element unit DEL, the voltagecontrol circuit 17 performs control to make the difference between thevoltage Va of the first electrode unit 31 and the voltage Vk of thesecond electrode unit 32 closer to the forward-bias light-emitting drivevoltage ΔVFL. As illustrated in FIG. 19, the voltage control circuit 17applies a forward-bias voltage of equal to or larger than thelight-emitting drive voltage ΔVFL between the first electrode unit 31and the second electrode unit 32.

As illustrated in FIG. 19, the first electrode driver 14 applies thedrive signal pulse Sg to the first electrode unit 31. The secondelectrode driver 15 applies the drive signal pulse Sg to a part of thesecond electrode unit 32 overlapping in planar view with a part of thefirst electrode unit 31 to which the first electrode driver 14 appliesthe drive signal pulse Sg. Even when the drive signal pulse Sg isapplied in the drive selection period Htx, this configuration makes thepotential difference between the first electrode unit 31 and the secondelectrode unit 32 equal to or larger than the light-emitting drivevoltage ΔVFL. Even when the drive signal pulse Sg is applied, the firstlight-emitting element unit DEL continues to emit light. The lightingamount of the first light-emitting element unit DEL varies depending onthe voltage Vk of the second electrode unit 32 controlled by the voltagecontrol circuit 17 based on an instruction from the control unit 11.

As described above, in the input device 2 according to the firstembodiment and the modifications thereof, the first electrode unit 31includes a plurality of first conductive layers formed in one layer, andthe second electrode unit 32 includes a plurality of second conductivelayers each having a size overlapping with one of the first conductivelayers of the first electrode unit 31 in planar view. The drive signalpulses Sg rising in the same direction are applied to one of the firstconductive layers of the first electrode unit 31 and one of the secondconductive layers of the second electrode unit 32 overlapping with eachother in planar view.

Specifically, the input device 2 according to the first embodiment andthe modifications thereof includes the first electrode driver 14, thesecond electrode driver 15, and the proximity detecting unit 40. Thefirst electrode driver 14 supplies a voltage to the first electrode unit31. The second electrode driver 15 supplies a voltage to the secondelectrode unit 32. The proximity detecting unit 40 detects a change inthe electric field between the first electrode unit 31 and the thirdelectrode unit 33 depending on the coordinates of the proximity objectpresent at a position overlapping with the first surface 201 of thefirst substrate 21 in planar view as the proximity detection signal Vdetin response to the drive signal pulse Sg. As described above, the firstelectrode driver 14 and the second electrode driver 15 scan, in atime-division manner, a part of the first electrode unit 31 and a partof the second electrode unit 32 overlapping with each other in planarview as the drive electrode Tx and the drive electrode Tz, respectively,to supply the drive signal pulse Sg.

In a case where the input device 2 according to the first embodiment andthe modifications thereof does not function as a front light, the secondelectrode driver 15 applies no forward-bias voltage between the firstelectrode unit 31 and the second electrode unit 32, thereby applying nolight-emitting drive voltage ΔVFL. In this case, even when the drivesignal pulse Sg is applied to the first electrode unit 31 and the secondelectrode unit 32 in the input device 2, emission of light from thefirst light-emitting element unit DEL is suppressed.

On the other hand, in a case where the input device 2 according to thefirst embodiment and the modifications thereof function as a frontlight, the second electrode driver 15 applies a forward-bias voltagebetween the first electrode unit 31 and the second electrode unit 32,thereby applying the light-emitting drive voltage ΔVFL. As a result, thefirst light-emitting element unit DEL emits light. The second electrodedriver 15 controls the voltage value equal to or larger than thelight-emitting drive voltage ΔVFL, thereby controlling the lightingamount of the first light-emitting element unit DEL. In this case, evenwhen the drive signal pulse Sg is applied to the first electrode unit 31and the second electrode unit 32 in the input device 2, the firstlight-emitting element unit DEL continues to emit light.

Second Embodiment

The following describes drive control of the input device 2 according toa second embodiment of the present invention with reference to FIGS. 1,6, 7, 20, and 21. In the following description, the input device 2according to the second embodiment is explained using the input device 2according to the first embodiment as an example. The technologyaccording to the second embodiment is also applicable to any of theinput devices described in the modifications of the first embodiment.FIG. 20 is a diagram for explaining the first drive electrode driver andthe second drive electrode driver according to the second embodiment.The first electrode unit 31 serves as a cathode of the firstlight-emitting element unit DEL, whereas the second electrode unit 32serves as an anode of the first light-emitting element unit DEL.Components identical with those described in the first embodiment andthe modifications thereof are denoted by like reference numerals, andoverlapping explanation thereof will be omitted.

As illustrated in FIG. 20, the first electrode driver 14 according tothe second embodiment includes the first electrode control unit 141, aTx timing synthesis circuit 19, and the Tx buffer 16. The firstelectrode control unit 141 generates the drive signal Vtx based on thecontrol signal supplied from the control unit 11 and supplies it to theTx timing synthesis circuit 19 and an EL lighting timing generationcircuit 18. The control unit 11 transmits a display synchronizationsignal Vp and a lighting amount signal Vg for lighting the display unit9 to the EL lighting timing generation circuit 18. The displaysynchronization signal Vp is a request signal for causing the firstlight-emitting element unit DEL to emit light in synchronization withupdate of display. Based on the display synchronization signal Vp, theEL lighting timing generation circuit 18 generates a pulse signal ELreqof a lighting period corresponding to the lighting amount signal Vg. TheEL lighting timing generation circuit 18 generates the pulse signalELreq of the lighting period having a pulse width corresponding to thelighting amount of the first light-emitting element unit DEL by settinga lighting period to be a high level (H) and a non-lighting period to bea low level (L), for example. The EL lighting timing generation circuit18 then supplies the pulse signal ELreq to the Tx timing synthesiscircuit 19. When the drive signal Vtx is supplied to the EL lightingtiming generation circuit 18, the pulse of the drive signal Vtx issuperimposed on the pulse signal ELreq of the lighting period.

The second electrode driver 15 includes the second electrode controlunit 151 and the voltage control circuit 17. The second electrodecontrol unit 151 supplies electric power at a constant voltage to thevoltage control circuit 17. The voltage control circuit 17 controls thevoltage supplied to the second electrode unit 32 of the input device 2based on the control signal supplied from the control unit 11.

To turn off the first light-emitting element unit DEL, the voltagecontrol circuit 17 according to the second embodiment makes the voltageVa of the second electrode unit 32 closer to the voltage Vk of the firstelectrode unit 31 (refer to FIG. 16). Even if the first light-emittingelement unit DEL is turned on, the voltage control circuit 17 maintainsthe voltage without any change.

FIG. 21 is a timing chart of drive control according to the secondembodiment. As illustrated in FIG. 21, in a first period H1, the drivesignal Vtx transmitted from the first electrode control unit 141 doesnot coincide with the pulse signal ELreq of the lighting period. In thefirst period H1, the first electrode driver 14 applies the drive signalpulse Sg to a part of the first conductive layers (drive electrode Txn)of the first electrode unit 31 in response to the drive signal Vtx. Thesecond electrode driver 15 applies the drive signal pulse Sg to thesecond conductive layer (drive electrode Tzn) of the second electrodeunit 32 overlapping with the drive electrode Txn in planar view inresponse to the drive signal Vtx. In this case, even when the drivesignal pulse Sg is applied in the drive selection period Htx, thisconfiguration prevents the potential difference between the firstelectrode unit 31 and the second electrode unit 32 from exceeding thelight-emitting drive voltage ΔVFL at which the first light-emittingelement unit DEL is turned on, thereby suppressing emission of lightfrom the first light-emitting element unit DEL. As a result, the firstelectrode driver 14 and the second electrode driver 15 perform drivingto sequentially scan the drive electrodes Tx and the drive electrodesTz, respectively, in a time-division manner, thereby suppressingemission of light from the first light-emitting element unit DEL causedby either of the drive signal pulses Sg.

In the first period H1, a lighting pulse Sel is supplied to the driveelectrode Tzn (a part of the first electrode unit 31) of the inputdevice 2 based on the pulse signal ELreq of the lighting period. Thelighting pulse Sel makes a voltage difference between the firstelectrode unit 31 and the second electrode unit 32. When the voltagedifference reaches the forward-bias light-emitting drive voltage ΔVFL,the first light-emitting element unit DEL emits light. The lightingpulse Sel may be composed of a plurality of pulses, and the lightingamount of the first light-emitting element unit DEL may be controlled bypulse-width modulation.

As described above, when receiving the display synchronization signalVp, the EL lighting timing generation circuit 18 generates the pulsesignal ELreq of the lighting period. If the drive signal Vtx coincideswith the request signal for the lighting pulse Sel (displaysynchronization signal Vp), a rise of the drive signal Vtx transmittedfrom the first electrode control unit 141 coincides with a rise of thepulse signal ELreq of the lighting period in a second period H2illustrated in FIG. 21. In the second period H2, the lighting pulse Selon which the drive signal pulse Sg is superimposed is applied to a partof the second conductive layers (drive electrode Tzn) of the secondelectrode unit 32 based on the signal obtained by superimposing thedrive signal Vtx on the pulse signal ELreq of the lighting period. Inother words, even if the drive signal pulse Sg is superimposed, theforward-bias light-emitting drive voltage ΔVFL is applied between thefirst electrode unit 31 and the second electrode unit 32 by the lightingpulse Sel. As a result, the first light-emitting element unit DEL emitslight.

In the second period H2, the first electrode driver 14 applies the drivesignal pulse Sg to a part of the first conductive layers (driveelectrode Txn) of the first electrode unit 31 in response to the drivesignal Vtx. The second electrode driver 15 applies the drive signalpulse Sg to the second conductive layer (drive electrode Tzn) of thesecond electrode unit 32 overlapping with the drive electrode Txn inplanar view in response to the drive signal Vtx. Even if the drivesignal pulse Sg is applied in the drive selection period Htx, the firstlight-emitting element unit DEL can emit light when the potentialdifference between the first electrode unit 31 and the second electrodeunit 32 reaches the light-emitting drive voltage ΔVFL.

As illustrated in FIG. 21, in a third period H3, the drive signal Vtxtransmitted from the first electrode control unit 141 coincides with thepulse signal ELreq of the lighting period. In the third period H3, thedrive selection period Htx coincides with the required lighting period.In the third period H3, the lighting pulse Sel on which the drive signalpulse Sg is superimposed is applied to a part of the second conductivelayers (drive electrode Tzn) of the second electrode unit 32 based onthe signal obtained by superimposing the drive signal Vtx on the pulsesignal ELreq of the lighting period. Even if the drive signal pulse Sgis superimposed, the forward-bias light-emitting drive voltage ΔVFL isapplied between the first electrode unit 31 and the second electrodeunit 32 by the lighting pulse Sel. As a result, the first light-emittingelement unit DEL emits light.

In the third period H3, the first electrode driver 14 applies the drivesignal pulse Sg to a part of the first conductive layers (driveelectrode Txn) of the first electrode unit 31 in response to the drivesignal Vtx. The second electrode driver 15 applies the drive signalpulse Sg to the second conductive layer (drive electrode Tzn) of thesecond electrode unit 32 overlapping with the drive electrode Txn inplanar view in response to the drive signal Vtx. Even if the drivesignal pulse Sg is applied in the drive selection period Htx, the firstlight-emitting element unit DEL can emit light when the potentialdifference between the first electrode unit 31 and the second electrodeunit 32 reaches the light-emitting drive voltage ΔVFL.

As illustrated in FIG. 21, in a fourth period H4, a rise of the drivesignal Vtx transmitted from the first electrode control unit 141coincides with a fall of the pulse signal ELreq of the lighting period.If the drive signal Vtx is superimposed on the pulse signal ELreq of thelighting period, the drive signal Vtx does not coincide with the pulsesignal ELreq of the lighting period. When the lighting pulse Selamplified and generated from the pulse signal ELreq of the lightingperiod is applied to a part of the second conductive layers (driveelectrode Tzn) of the second electrode unit 32 of the input device 2,the first light-emitting element unit DEL emits light. In other words,the forward-bias light-emitting drive voltage ΔVFL is applied betweenthe first electrode unit 31 and the second electrode unit 32 by thelighting pulse Sel. As a result, the first light-emitting element unitDEL emits light.

In the fourth period H4, the first electrode driver 14 applies the drivesignal pulse Sg to a part of the first conductive layers (driveelectrode Txn) of the first electrode unit 31 in response to the drivesignal Vtx. The second electrode driver 15 applies the drive signalpulse Sg to the second conductive layer (drive electrode Tzn) of thesecond electrode unit 32 overlapping with the drive electrode Txn inplanar view in response to the drive signal Vtx. Even if the drivesignal pulse Sg is applied in the drive selection period Htx, thepotential difference between the first electrode unit 31 and the secondelectrode unit 32 is smaller than the light-emitting drive voltage ΔVFLat which the first light-emitting element unit DEL emits light. As aresult, it is possible to suppress emission of light from the firstlight-emitting element unit DEL.

Modification of the Second Embodiment

The following describes drive control of the input device 2 according toa modification of the second embodiment with reference to FIGS. 1, 6, 7,and 20 to 22. In the following description, the input device 2 accordingto the modification of the second embodiment is explained using theinput device 2 according to the first embodiment as an example. Thetechnology according to the modification of the second embodiment isalso applicable to any of the input devices described in themodifications of the first embodiment. FIG. 22 is a timing chart ofdrive control according to the modification of the second embodiment.Components identical with those described in the first embodiment, thesecond embodiment, and the modifications of the first embodiment aredenoted by like reference numerals, and overlapping explanation thereofwill be omitted.

As illustrated in FIG. 22, by performing the same drive control as thatin the first period H1 described in the second embodiment, it ispossible to carry out both lighting drive and proximity detection drivein the first period H1. Detailed description will be omitted for thedrive control in the first period H1 performed by the input device 2according to the modification of the second embodiment.

In the second period H2, the EL lighting timing generation circuit 18replaces the pulse signal ELreq of the lighting period with a pulsesignal ELon of the lighting period delayed by a period not coincidingwith the drive signal Vtx (e.g., a period twice as long as the driveselection period Htx). The EL lighting timing generation circuit 18 thentransmits the pulse signal ELon to the voltage control circuit 17. Basedon the drive signal Vtx, the voltage control circuit 17 supplies theamplified drive signal pulse Sg to the drive electrode Tzn (a part ofthe second electrode unit 32) sequentially selected in the scanningdirection Scan. Subsequently, the voltage control circuit 17 generatesthe lighting pulse Sel based on the pulse signal ELon of the lightingperiod. When the voltage control circuit 17 applies the lighting pulseSel to a part of the second conductive layers (drive electrode Tzn) ofthe second electrode unit 32 of the input device 2, the firstlight-emitting element unit DEL emits light. In other words, theforward-bias light-emitting drive voltage ΔVFL is applied between thefirst electrode unit 31 and the second electrode unit 32 by the lightingpulse Sel, whereby the first light-emitting element unit DEL emitslight.

In the second period H2, the first electrode driver 14 applies the drivesignal pulse Sg to a part of the first conductive layers (driveelectrode Txn) of the first electrode unit 31 in response to the drivesignal Vtx. As described above, the second electrode driver 15 appliesthe drive signal pulse Sg to the second conductive layer (driveelectrode Tzn) of the second electrode unit 32 overlapping with thedrive electrode Txn in planar view in response to the drive signal Vtx.Even if the drive signal pulse Sg is applied in the drive selectionperiod Htx, the potential difference between the first electrode unit 31and the second electrode unit 32 is smaller than the light-emittingdrive voltage ΔVFL at which the first light-emitting element unit DELemits light. As a result, it is possible to suppress emission of lightfrom the first light-emitting element unit DEL.

In the third period H3, the pulse signal ELreq of the lighting period isdivided into a first pulse signal ELon1 of the lighting period and asecond pulse signal ELon2 of the lighting period delayed by a period notcoinciding with the drive signal Vtx (e.g., a period twice as long asthe drive selection period Htx). The pulse signal ELreq of the lightingperiod is replaced by the first pulse signal ELon1 of the lightingperiod and the second pulse signal ELon2 of the lighting period. Thevoltage control circuit 17 generates a first lighting pulse Sel1corresponding to the first pulse signal ELon1 of the lighting period.Based on the drive signal Vtx, the voltage control circuit 17 suppliesthe amplified drive signal pulse Sg to the drive electrode Tzn (a partof the second electrode unit 32) sequentially selected in the scanningdirection Scan. Subsequently, the voltage control circuit 17 generates asecond lighting pulse Sel2 corresponding to the second pulse signalELon2 of the lighting period. When the voltage control circuit 17applies the first lighting pulse Sel1 and the second lighting pulse Sel2to a part of the second conductive layers (drive electrode Tzn) of thesecond electrode unit 32 of the input device 2, the first light-emittingelement unit DEL emits light. In other words, the forward-biaslight-emitting drive voltage ΔVFL is applied between the first electrodeunit 31 and the second electrode unit 32 by the first lighting pulseSel1 and the second lighting pulse Sel2, whereby the firstlight-emitting element unit DEL emits light.

In the third period H3, the first electrode driver 14 applies the drivesignal pulse Sg to a part of the first conductive layers (driveelectrode Txn) of the first electrode unit 31 in response to the drivesignal Vtx. As described above, the second electrode driver 15 appliesthe drive signal pulse Sg to the second conductive layer (driveelectrode Tzn) of the second electrode unit 32 overlapping with thedrive electrode Txn in planar view in response to the drive signal Vtx.Even if the drive signal pulse Sg is applied in the drive selectionperiod Htx, the potential difference between the first electrode unit 31and the second electrode unit 32 is smaller than the light-emittingdrive voltage ΔVFL at which the first light-emitting element unit DELemits light. As a result, it is possible to suppress emission of lightfrom the first light-emitting element unit DEL.

As illustrated in FIG. 22, by performing the same drive control as thatin the fourth period H4 described in the second embodiment, it ispossible to carry out both lighting drive and proximity detection drivein the fourth period H4. Detailed description will be omitted for thedrive control in the fourth period H4 performed by the input device 2according to the modification of the second embodiment.

As described above, if the drive signal Vtx for generating the drivesignal pulse Sg coincides with the request signal for the lighting pulseSel (display synchronization signal Vp), the second electrode driver 15divides the lighting pulse into a front part and a rear part. The secondelectrode driver 15 then applies the first lighting pulse Sel1 resultingfrom the division, the drive signal pulse Sg, and the second lightingpulse Sel2 resulting from the division in this order to the secondelectrode unit 32. When scanning the drive electrodes Tz in atime-division manner during a period of which lighting is beingrequested, the second electrode driver 15 gives priority to applicationof the drive signal pulse Sg over application of the lighting pulse Selto delay the application of the lighting pulse Sel. With thisconfiguration, the drive signal pulse Sg does not virtually coincidewith the lighting pulse Sel. It is thus possible to carry out both driveof the drive electrodes Tx and emission of light from the firstlight-emitting element unit DEL.

In any of the first period H1, the second period H2, the third periodH3, and the fourth period H4, the first electrode driver 14 and thesecond electrode driver 15 can supply the drive signal pulse Sg at aconstant timing regardless of whether the first light-emitting elementunit DEL is turned on or off. As a result, the accuracy of proximitydetection performed by the input device 2 does not vary depending onwhether the first light-emitting element unit DEL is turned on or off.

Described above is the case where the drive signal Vtx is applied to thedrive electrodes Tx and the drive electrodes Tz as one pulse. Also in acase where the drive signal Vtx is applied as a plurality of pulses, itis possible to carry out both lighting drive and proximity detectiondrive in the first period H1, the second period H2, and the fourthperiod H4 by performing the same drive control in the first period H1,the second period H2, and the fourth period H4 as described in themodification of the second embodiment.

In the second embodiment and the modification thereof, the firstelectrode unit 31 serves as a cathode of the first light-emittingelement unit DEL, and the second electrode unit 32 serves as an anode ofthe first light-emitting element unit DEL. Alternatively, the firstelectrode unit 31 may serve as an anode of the first light-emittingelement unit DEL, and the second electrode unit 32 may serve as acathode of the first light-emitting element unit DEL.

While exemplary embodiments of the present invention have beendescribed, the embodiments are not intended to limit the invention. Thecontents disclosed in the embodiments are given by way of example only,and various changes can be made without departing from the spirit of theinvention. Appropriate changes made without departing from the spirit ofthe invention naturally fall within the technical scope of theinvention.

The luminescent layer 22, for example, is not limited to an organiclayer and may be an inorganic layer. The luminescent layer may belight-emitting diodes. The luminescent layer 22 may be a layer obtainedby vapor-depositing a plurality of layers to emit white light or a layerin which luminescent layers of R, G, and B are separately provided. Inthe case of the luminescent layer 22 in which a plurality of colors,such as R, G, and B, are arranged on a single plane to display white,light-emitting element units of the respective colors have differentoptimum current values. In a case where the current values are optimizedby the light-emitting element units of the respective colors in theinput device 2, the light-emitting element units of the same color arepreferably arranged on a single conductive layer in the first electrodeunit 31. This configuration can facilitate optimization of the currentvalue.

The first conductive layers of the first electrode unit 31, the secondconductive layers of the second electrode unit 32, and the thirdconductive layers of the third electrode unit each may be a single layeror a laminated body composed of a plurality of layers.

The input device 2 according to the first and the second embodiments andthe modifications thereof is applicable to electronic apparatuses ofvarious fields, such as television apparatuses, digital cameras,notebook personal computers, portable electronic apparatuses includingmobile phones, and video cameras. In other words, the display device 1with a proximity detecting function including the input device 2according to the first and the second embodiments and the modificationsthereof and the display unit 9 is applicable to electronic apparatusesof various fields that display video signals received from the outsideor video signals generated inside thereof as an image or video.

What is claimed is:
 1. An input device comprising: a first substratehaving a first surface and a second surface; a light-emitting elementunit including a first electrode unit formed on the second surface andincluding a plurality of first conductive layers formed in one layer, asecond electrode unit formed in a layer different from the layer of thefirst electrode unit and including a plurality of second conductivelayers each having a size overlapping with one of the first conductivelayers in planar view, and a plurality of luminescent layerselectrically in contact with at least a part of the first electrodeunit, each of the luminescent layers being provided between the firstelectrode unit and the second electrode unit and being electrically incontact with one of the first conductive layers and one of the secondconductive layers overlapping with the first conductive layer in planarview; and a third electrode unit insulated from the first conductivelayers and that detects a change in an electric field between the firstconductive layers and the third electrode unit depending on coordinatesof a proximity object present at a position overlapping with the firstsurface in planar view.
 2. The input device according to claim 1,wherein the third electrode unit includes a plurality of thirdconductive layers formed in one layer different from the layer of thefirst conductive layers.
 3. The input device according to claim 1,wherein the first conductive layers have a shape continuously extendingin one direction in planar view and are in contact with the luminescentlayers along the shape of the first conductive layers, and thelight-emitting element unit is capable of emitting light along the shapeof the first conductive layers.
 4. The input device according to claim1, wherein the light-emitting element unit includes a light-blockingunit provided closer to the first surface than the luminescent layer. 5.The input device according to claim 4, wherein the light-blocking unitis made of a metal material having metallic luster.
 6. The input deviceaccording to claim 1, wherein the luminescent layer is an organicluminescent layer.
 7. The input device according to claim 1, wherein thefirst electrode unit, the second electrode unit, and the third electrodeunit are provided on the second surface of the first substrate.
 8. Theinput device according to claim 1, wherein the third electrode unit isprovided on the first surface of the first substrate, and the firstelectrode unit and the second electrode unit are provided on the secondsurface of the first substrate.
 9. The input device according to claim8, further comprising: a cover substrate facing the first surface of thefirst substrate, wherein the third electrode unit is provided on thecover substrate.
 10. An input device comprising: a first substratehaving a first surface and a second surface; a light-emitting elementunit including a first electrode unit formed on the second surface andincluding a plurality of first conductive layers formed in one layer, asecond electrode unit formed in a layer different from the layer of thefirst electrode unit and including a plurality of second conductivelayers each having a size overlapping with one of the first conductivelayers in planar view, and a plurality of luminescent layerselectrically in contact with at least a part of the first electrodeunit, each of the luminescent layers being provided between the firstelectrode unit and the second electrode unit and being electrically incontact with one of the first conductive layers and one of the secondconductive layers overlapping with the first conductive layer in planarview; and a third electrode unit insulated from the first conductivelayers and that detects a change in an electric field between the firstconductive layers and the third electrode unit depending on coordinatesof a proximity object present at a position overlapping with the firstsurface in planar view, wherein a drive signal pulse rising in the samedirection is applied to the first conductive layers and the secondconductive layers overlapping with each other in planar view.
 11. Theinput device according to claim 10, further comprising: a firstelectrode driver that supplies a voltage to the first electrode unit; asecond electrode driver that supplies a voltage to the second electrodeunit; and a proximity detecting unit that processes the change in theelectric field between the first electrode unit and the third electrodeunit depending on the coordinates of the proximity object present at theposition overlapping with the first surface of the first substrate inplanar view as a proximity detection signal in response to the drivesignal pulse, wherein the first electrode driver and the secondelectrode driver scan, in a time-division manner, the first conductivelayers and the second conductive layers overlapping with each other inplanar view as drive electrodes to supply the drive signal pulse. 12.The input device according to claim 11, wherein, when a drive signal forgenerating the drive signal pulse coincides with a request signal for alighting pulse, the second electrode driver superimposes the drivesignal pulse on the lighting pulse.
 13. The input device according toclaim 11, wherein, when a drive signal for generating the drive signalpulse coincides with a request signal for a lighting pulse, the secondelectrode driver divides the lighting pulse into a front part and a rearpart and then sequentially applies a first lighting pulse resulting fromthe division, the drive signal pulse, and a second lighting pulseresulting from the division to the second electrode unit.
 14. A displaydevice comprising: an input device including: a first substrate having afirst surface and a second surface; a light-emitting element unitincluding a first electrode unit formed on the second surface andincluding a plurality of first conductive layers formed in one layer, asecond electrode unit formed in a layer different from the layer of thefirst electrode unit and including a plurality of second conductivelayers each having a size overlapping with one of the first conductivelayers in planar view, and a plurality of luminescent layerselectrically in contact with at least a part of the first electrodeunit, each of the luminescent layers being provided between the firstelectrode unit and the second electrode unit and being electrically incontact with one of the first conductive layers and one of the secondconductive layers overlapping with the first conductive layer in planarview; and a third electrode unit insulated from the first conductivelayers and that detects a change in an electric field between the firstconductive layers and the third electrode unit depending on coordinatesof a proximity object present at a position overlapping with the firstsurface in planar view; and a display unit provided on the secondsurface of the input device and capable of displaying an image on thefirst surface thereof.